<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        document.write('')
        document.write('<h1>我是标题</h1>')
        alert('警告！警告！')
        console.log('这是控制台日志') //控制台日志输出
        prompt('请输入语句')
    </script>
</body>

</html>